ThermaTwin is unique in that it uses a specially produced flexible food grade silicone tube, rather than a copper or alluminium pipe to transfer the water through the solar panel. Even though the system uses only water (glycol free) and can thus freeze, it does no damage, and as soon as the sunlight hits the panel, the absorber plates begin to thaw the water and the panel is available to produce hot water; even on a cold day (see; How does it work?).
As an added safety feature, the pump does not run if the panel is colder than the water tank, and there is a built in bypass so that even if the pump inadvertently starts when part of the panel is still frozen, the water does not over pressurise the pipework.
The simplicity of the system and the elimination of a drain-back control and anti-freeze from the water enables ThermaTwin to ‘punch above its weight’ in terms of performance compared to glycol treated systems, and the heated water to feed directly to the showers and baths if required.